<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<script>

    let m = new Map([
        [123,'后盾人'],
        ['rn','react native']
    ]);

    console.log(m.get(123));

</script>



</body>
</html>